Pledge Contract of Maximum Amount

Exhibit 10.13

Pledge Contract of Maximum Amount

No. Shenfa Longgang E’zhi Zi 20060329001-2

In order to secure the indebtedness of Shenzhen BAK Battery Co., Ltd. (hereinafter referred to as Obligor) under the Comprehensive Credit Facilities Agreement (reference no. Shenfa Longgang Zongzi 20060329001, hereinafter referred to as Master Agreement) entered into by Creditor and Obligor on 5 April 2006, the Pledger agrees to provide its assets to the Creditor as the pledge. Through friendly negotiation, both parties agree to enter into this Contract:

I. Scope of Guaranty

The scope of guaranty covers all loan principal, interest, penalty interest and all the expenses incurred to the Creditor in realizing its creditor’s right. The maximum loan principal shall not exceed RMB 150 Million yuan.

II. Pledged Collaterals

The detail information of the pledged collaterals is described in the Statement of Pledged Collaterals attached to this Contract.

After the Pledger has pledged the abovementioned collaterals, the Pledger shall not

transfer such pledged collaterals or allow any third party to use such pledged collaterals without the approval of the Creditor. In case that the Creditor and Pledger agree to transfer the pledged collaterals, the payment received by the Pledger from such transaction shall be used to settle the indebtedness owed to the Creditor in advance to expiry or be deposited in a third party designated by both parties.

III. The Creditor is entitled to dispose of the pledged collaterals by means of settlement of the indebtedness in kind, auction or sale and use the payment derived from such disposal to repay the indebtedness owed to it if any of the following occurs:

IV. Undertakings and Representations of the Pledger

The Pledger is legally qualified to execute and perform this Contract, and has obtained all necessary authorization by the board of directors or other competent authorities (as the case may be).

The Pledger undertakes that all application materials submitted by it to the Creditor are truthful, lawful, effective and with no serious errors or omissions. The Pledger has the lawful and undisputed right to pledge the pledged collaterals under this Contract. The execution and performance of this Contract by the Pledger do not violate any other contracts entered into or being performed by the Pledger.

The Pledger also undertakes that all application materials submitted by the Obligor to the Creditor are truthful, lawful, effective and with no serious errors or omissions.

The Pledger shall notify the Creditor in writing within 10 days after it has changed its address, contact details, liaison telephone, business scope or legal representative etc.

The Pledger has fully understood all provisions of this Contract and both parties execute this Contract of their free will.

V. The guaranty of pledge provided by the Pledger is independent from and shall not be replaced by any other guaranty provided by other guarantors.

VI. In case that part or whole of the Master Agreement or agreement entered into under the Master Agreement become invalid due to any reason, the Obligor shall nevertheless perform its obligation of repayment and the Pledger shall perform its obligation of guaranty for the Obligor’s obligation of repayment in accordance with this Contract.

VII. The expenses incurred during the course of execution and performance of this Contract by both parties such as notarial or testimonial fee, registration fee, auction or sell cost etc. shall all be born by the Pledger.

VIII. Amendment and Termination of Contract

IX. Applicable Law and Dispute Settlement

X. This Contract shall be signed and stamped by both parties (only signature is needed for party of natural person). This Contract shall become effective upon the delivery of the pledged collaterals to the Creditor. If the pledge shall be registered or recorded in accordance with article 78 or 79 of the Guarantee Law of People’s Republic of China, this Contract shall become effective upon the registration or record.

XI. Other Issues

XII. This Contract has four originals, the Creditor shall retain two originals, the Obligor shall retain one original and the Guarantor shall retain one original.

Statement of Pledged Collaterals

The Pledger undertakes that the above statement is truthful. The Pledger shall bear the joint and several liability for the indebtedness of the Obligor under the Master Agreement if the pledge is invalid or the value of the pledged collaterals is not sufficient to cover the indebtedness due to false statement by the Pledger.